Adjustable pitman arm



Oct. 3, 1944.

T. J. OLIVER ADJUSTABLE PITMAN ARM Filed Feb. 26, 1945 jiillmij Flea.

INVENTOE THO AS J. OLIVER B3. d w

ATTOR Y Patented Oct. 3, 1944 UNITED STATES PATENT OFFICE ADJUSTABLE PITMAN ARM Thomas J. Oliver, Birmingham, Ala.

Application February 26, 1943, Serial No. 477,269

2 Claims.

This invention relates to an adjustable pitman arm for a loom and has for its object the provision of a device of the character designated which is simple of construction and manipulation and which shall be adapted to provide a quick, close adjustment of the arm.

As is well known in the art to which my invention relates, it is very important that the lay of the loom run true or square with the loom. If either of the pitman arms is longer than the other, even but a slight amount, the shuttle is liable to go crooked and fly out. Also, it is essential in automatic looms, for the shuttle to be directly under the transferrer when the change is called. Otherwise, the bobbin may roll out at the front or back. It is accordingly important that means be provided for quickly and accurately adjusting the length of the pitman arms so that the lay may be trued up.

In accordance with my invention, I provide an adjustable pitman arm comprising U-shaped metal straps forming the ends of the arm, with means for holding the straps in adjusted, fixed, relative positions. Within the straps, I provide movable inserts, which may be made of wood, and which cooperate with the straps to form bearings at the ends of the arm. An eccentric pin is mounted in suitable bearings between the inner ends of the inserts and controls the relative positions of said inserts, and thereby the efiective length of the pitman arm, the straps being taken up to conform to the positions of the inserts. The eccentric may be turned to adjust the position of the inserts and held in adjusted position.

A device embodying these and other features of my invention is illustrated in the accompanying drawing, forming a part of this application, in which;

Fig. 1 is a top plan view of a pitman arm having my improved adjusting means incorporated therein;

Fig. 2 is a side elevational view of the same;

Fig. 3 is a sectional view taken along the line III-III of Fig. 1; and

Fig. 4 is a sectional view taken along the line IV-IV of Fig. 2.

Referring to the drawing, my improved arm comprises a rear U-shaped strap I and a similar front strap II forming the ends of the arm. Instead of the unitary insert heretofore employed, I provide an insert I2 preferably made of wood which fits into the strap Ill, and a similar insert I3 which fits into the strap II. The inserts I2 and I3 are shaped at their ends to cooperate with the straps I0 and II to form bearings I5 and 20 respectively. The strap I0 is provided at its .ends with flanges I4 and I6, and the strap II is provided with similar flanges I1 and I8. The flange I4 is joined to the flange H, by means of a bolt I9, with a securing nut 2I and a lock nut22 thereon. Likewise, the flanges I6 and I8 are joined by a bolt 23 with a securing nut 24 and a lock nut 26 thereon, whereby the straps I0 and I I may be firmly held in adjusted position. Near the outer end of the pitman arm the strap I0 is provided with elongated holes 21 and the insert I2 is provided with a hole 28 registering with the holes 21. A bolt 29, with a nut 3I thereon, passes through the holes 21 and 28 and holds the insert I2 firmly in adjusted position with respect to the strap I0. Similarly, the strap II is provided with elongated holes 32 therein and the insert I3 is provided with a registering hole 33 through which a bolt 34 passes having a nut 36 thereon, which nut and bolt hold the insert I3 in adjusted position with respect to the strap I i.

Secured to the strap I0, as by welding, on the opposite sides thereof, are plates 31 and 38, which overlap the associated ends of the inserts I2 and I3. Bolts 39 and 4| pass through the plates 31 and 38, and through slotted holes 42 and 43, in inserts I2 and I3 respectively, to hold the inserts in adjusted position in a vertical plane.

Mounted in the plates 31 and 38, and adapted to bear against the associated ends of the inserts I2 and I3, is a pin 44, having an eccentric portion 46 intermediate its ends. On one end of the pin 44 is a head 41, having a socket 48 therein, to receive a suitable tool. A bearing ring 49 for the head 41, is provided on the plate 38, and a set screw 5| passes through the ring 49 and engages the end of the pin 44 to hold it in adjusted position. On the opposite side of the arm, a bearing ring 52 is secured to the plate 37 and the opposite end of the pin 44 takes its bearing in said bearing ring. A set screw 53 mounted in the bearing ring 52 serves to aid the set screw 5| to hold the pin 44 in adjusted position.

As already mentioned, the insert I2 and strap Ill form the bearing I5 which, in operation is connected to the crank arm of the loom (not shown). The end insert I3 and strap II form the bearing 20 for connecting the other end of the pitman arm to the lay (not shown). Whenever it becomes necessary to true up the lay, the nut 2I, 24, 3| and 36 are loosened enough for the inserts I2 and I3 to be moved with respect to the straps quired position to provide the necessary length of the pitman arm. It will be noted that I provide sufiicient clearance, shown exaggerated at 58 and 59, between the straps Ill and II and the inserts l2 and I3 to permit easy movement of the inserts when the eccentric pin is turned. With the parts in adjusted position as just described, the nuts are all tightened up to hold them against displacement.

From the foregoing it will be apparent that I have devised an improved adjustable pitman arm which is simple of design and manipulation, and which includes an eccentrically mounted adjusting pin between the halves of the arm.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In an adjustable pitman arm, a pair of metal straps forming the ends of the arm, adjustable means for holding the straps in fixed relative positions, an insert in each of the straps movable with respect thereto and cooperating therewith to provide a bearing at each end of the arm, bearing plates joined to one of the straps and disposed on opposite sides of the straps to overlap the ends of the inserts, an eccentric pin mounted in the bearing plates and bearing against the inner ends of the inserts to control their positions relative to the straps, and mean to hold the eccentric pin in adjusted position.

2. In an adjustable pitman arm, a pair of U- shaped metal straps forming the ends of the arms, means for adjustably positioning the straps with respect to each other, a movable insert loosely mounted in each of the straps and cooperating therewith to form bearings at the ends, means for holding the straps and inserts in fixed relative positions, a bearing plate on each side of the straps and secured to one of the straps and disposed to overlap the ends of the inserts, an eccentric pin mounted in the bearing [plate and having its eccentric portion bearing against the adajcent ends of the inserts, and adjustable means for positioning the eccentric pin.

THOMAS J. OLIVER. 

